Atherosclerotic cardiovascular disease is the number one cause of morbidity and mortality in the western world. This may lead to arterial stenosis which may ultimately lead to occlusion. When this occurs, the consequences range from gangrene, to stroke or to myocardial infarction. At the moment, autologous saphenous veins are the treatment modality of choice in low blood flow vessels such as the coronary arteries and infrapopliteal vessels. However, in many cases the saphenous vein is either unsuitable or unavailable (due to previous stripping). In such a setting, the need for a compliant vessel prosthesis is vital. We propose to test in experimental animals a compliant, microporous small vessel prosthesis which has shown a low thrombogenic profile as well as a high biocompatibility index in preliminary trials. The compliant small vessel graft (4 mm I.D.) will be fabricated from our patented biostable polyurethane tradenamed ChronoFlex. The proposed graft will be evaluated in vivo by well-accepted techniques. The universal benefit of this research would be to create a clinically acceptable and hyperplasia- resistant small diameter prosthetic vascular graft.